Select the correct statement from those given below.

Options

A. Legumes are incapable of fixing nitrogen
B. Legumes fix nitrogen through bacteria living in fruits
C. Legumes fix nitrogen only by bacteria present in root nodules
D. All legumes have stem nodules

Answer

To solve the question of selecting the correct statement regarding legumes and nitrogen fixation, we can follow these steps:

### Step-by-Step Solution:

1. **Analyze the First Statement**:
- The first statement claims that "legumes are incapable of fixing nitrogen."
- This statement is incorrect because legumes are well-known for their ability to fix nitrogen through symbiotic relationships with nitrogen-fixing bacteria, particularly Rhizobium.

**Hint**: Remember that legumes have a symbiotic relationship with specific bacteria that help them fix nitrogen.

2. **Analyze the Second Statement**:
- The second statement states that "legumes fix nitrogen through bacteria living in fruits."
- This statement is also incorrect. Nitrogen fixation in legumes occurs in root nodules, not in fruits.

**Hint**: Consider where in the plant nitrogen fixation actually takes place.

3. **Analyze the Third Statement**:
- The third statement claims that "legumes fix nitrogen only by bacteria present in root nodules."
- This statement is correct. Legumes form root nodules where nitrogen-fixing bacteria reside, and this is the primary site of nitrogen fixation.

**Hint**: Focus on the specific location within the plant where nitrogen fixation occurs.

4. **Analyze the Fourth Statement**:
- The fourth statement suggests that "all legumes will have stem nodules."
- This statement is incorrect because not all legumes have stem nodules; the primary nitrogen fixation occurs in root nodules.

**Hint**: Think about the common characteristics of legumes and their nodules.

### Conclusion:
The correct statement among the provided options is the third statement: "legumes fix nitrogen only by bacteria present in root nodules."